In the prior art it was desired to provide a shoe construction which simulated the natural walking conditions of primitive people by people today walking or running on hard, flat surfaces. The prior art sought, in effect, to provide a shoe which would be similar to running or walking on sand, wherein the sand fills in beneath the medial region of the foot as the lateral portion depresses on bearing the weight of the wearer.
One prior art attempt at achieving this effect was the "Earth Shoe." The Earth Shoe merely provides a recessed heel and a curved or rocker surface on the bottom of the shoe extending from a rectilinear generatrix which emanates from a point lying beneath the rear part of the location of the treading surface of the little toe obliquely rearwardly forming an angle of about 70.degree. to 90.degree. with a connecting line which extends from the point of the extreme part of the heel.
This form of footwear causes the foot during walking to shift the pressure on the ball of the foot onto the treading surface of the big toe instead of on the treading surface of the remaining four toes, thus allegedly providing a safer and less tiring walk.
As evident from the above discussion of the Earth Shoe, the footwear is fixed and does not accommodate changing conditions of the foot for the comfort of the user as to permit the foot and leg of the user to assume its natural position.
In Borgeas, U.S. Pat. No. 3,990,159, granted Nov. 9, 1976, there is described an improvement to the "Earth Shoe," wherein the foot supporting sole which is modifiable to reflect the changing conditions of the foot. While the Borgeas construction provided a readily modifiable insole, the forces reacting to the foot were the same resilient forces inherent in the foam rubber. And these resilient forces were uniform across the foam rubber insole.
Other prior art constructions were directed to cushions by permitting air flow patterns in relation to rubber sole, construction such as in Gilbert, U.S. Pat. Nos. 2,080,469, granted May 18, 1937; Famolare, Jr., 4,000,566, granted Feb. 22, 1977; Lee, U.S. Pat. No. 2,469,969, granted May 10, 1949; Russell, U.S. Pat. No. 3,087,261 granted Apr. 30, 1963; and Braun, U.S. Pat. No. 2,546,296, granted Mar. 27, 1951.
Now there is provided by the present invention, a shoe or shoe insole construction wherein there is dynamic action in proportion to the weight or force exerted by the wearer at different regions of the insole. The shoe or insole portion of the shoe provides a therapeutic supportive aspect to the foot, while cushioning and protecting the foot as well.
It is therefore a principal object of this invention to provide new and improved shoe which combines dynamic support and cushioning to the foot.
It is another object of this invention to provide a shoe as aforesaid which maintains the foot in an operable neutral position.
It is another object of this invention to provide a shoe, as immediately aforesaid, which will transfer the weight from one part of the foot to another.
It is still a further object of this invention to provide a shoe insole which dynamically forms an arch in situ with the weight distribution of the foot.
It is still a further object of this invention to provide a shoe which will diminish the likelihood of developing certain foot and leg deformities or conditions experienced in running or jogging on hard flat surfaces.
It is still a further object of this invention to provide a shoe which will exhibit improved comfort and support to persons having certain acquired or congenital deformities or conditions.
It is still a further object of this invention to provide a shoe which provides support and comfort to the foot particularly so in both the metatarsal head and lateral portions, while also providing improved stress relief in the medial region.
It is still a further object of this invention to provide a shoe insole construction which is lightweight.
It is still a further object of this invention to provide a therapeutic shoe which is readily constructed of relatively inexpensive materials, and yet is safe and practical in use.
It is still a further object of this invention to provide a shoe insole which is useful in a broad range of athletic footwear as well as normal walking footwear.